Field of the Disclosure
The present disclosure relates to processes for the preparation of sofosbuvir or its pharmaceutically acceptable salt, which employ novel intermediates. The present invention also provides novel intermediates of sofosbuvir and a process for the preparation thereof.
Description of the Related Art
Nucleoside phosphoramidates are inhibitors of RNA-dependent RNA viral replication and are useful as inhibitors of HCV NS5B polymerase, as inhibitors of HCV replication, and for treatment of hepatitis C infection in mammals. One example of a nucleoside phosphoramidate that inhibits HCV NS5B is sofosbuvir (also called PSI-7977). Sofosbuvir was developed by Pharmasset and is used for the treatment of chronic hepatitis C (CHC) infection, often as a component of a combination antiviral treatment regimen. Sofosbuvir is currently marketed in tablet form as SOVALDI®, in combination with ledipasvir in HARVONI®, and in combination with velpatasvir in EPCLUSA®, all by Gilead Sciences, Inc.
Sofosbuvir is chemically named (S)-isopropyl 2-((S)-(((2R,3R,4R,5R)-5-(2,4-dioxo3,4-dihydropyrimidin-1(2H)-yl)-4-fluoro-3-hydroxy-4-methyltetrahydrofuran-2yl)methoxy)-(phenoxy)phosphorylamino) propanoate and is represented by the following chemical structure (Formula-1):

Sofosbuvir and a process for its preparation are disclosed in U.S. Pat. No. 7,964,580 B2 and PCT Publication No. WO 2008/121634 A2, which are hereby incorporated by reference. The present disclosure provides a novel process for the preparation of sofosbuvir or its pharmaceutically acceptable salts that employs novel intermediates.